Dionysia

The Dionysia was also a four-day festival (held in Athens I believe) that originated in the sixth century B.C. The festival was held in honor of Dionysus the patron god of the stage. This festival displayed the writing talents of Aeschylus, Sophocles and others until the fall of Athens to Sparta in the late fifth century B.C. After the fall Greek culture pretty much went down the tubes.

Any of the festivals held in honor
of the Olympian god Dionysus. They correspond to the Roman
Bacchanalia; the greater Dionysia were held at Athens in March or
April, and were celebrated with elaborate performances of both
tragedies and comedies.